Such a pivotable hitch is known from DE-A 100 23 640. It comprises a curved tow bar, which is mounted movably around two rotatory axes and is pivoted to and fro by a motor drive between an extended operating position and a withdrawn inoperative position. The rotatory axes are actuated one after another, and the translatory drive first rotates the tow bar by 90° around an axis of rotation extending along the rear end of the bar by means of an eccentric lever for pivoting in from the operating position. The axis of rotation is directed vertically during this rotary movement, and the tow bar is moved during the rotary movement through a cutout necessary for this in the visible area of the rear spoiler of the towing vehicle. Due to the limited kinematics the tow bar cannot move about at the bottom around the edge of the rear spoiler or of the shock absorber and needs the optically disadvantageous cutout, which must be closed with a cover. As soon as the rotary movement comes to an end, a pivoting movement of the tow bar, which is not at right angles, takes place around a tilt axis directed in the longitudinal direction of the vehicle, as a result of which the tow bar disappears behind the rear spoiler and is not visible any longer. This hitch is of a complicated design and requires a complicated control or bar guide to maintain the necessary sequence of movements during the rotation and tilting. The tilting movement may begin only after the conclusion of the rotary movement, because the tow bar would otherwise strike the rear spoiler and damage same.
Another biaxially pivotable hitch is known from DE 195 21 896 A1. The tow bar is mounted pivotably around two rotatory axes that can be actuated one after another and is moved by a mechanical drive between an extended operating position and a withdrawn inoperative position at the towing vehicle. The tow bar is pivoted off from the operating position by means of filigree lifting clips and is subsequently rotated by 90° into a position behind the rear spoiler. The tow bar is visible from the outside in the inoperative position.
Another towing coupling, which has only a single, obliquely directed pivot axis for the movement of the tow bar, is known from EP-A 0 799 732. This arrangement requires a large space for its installation because the pivot axis is located obliquely in space. In addition, the tow bar also requires much free space for movement due to the monoaxial pivoting movement. Both are absent in many vehicles. The range of use is limited as a result.
Another hitch, in which the tow bar is likewise movable around two axes, but the translatory axis and a pivot axis cooperate, is known from DE-A 197 11 535. The drive generates a translatory extending movement from the inoperative position, and the tow bar is brought at the end of the movement into the upright position, which is needed in the extended operating position, by 90° from its initially transverse position by means of a helical crank. This arrangement only makes it possible to linearly withdraw the tow bar and to bring it from its position, in which it projects rearwardly from the rear of the vehicle in the operating position, into a position under the rear spoiler. However, it is not possible here to allow the tow bar to disappear in the inoperative position behind the rear spoiler and to make it invisible.